.\" SCCSID: @(#)vp.4	8.1	9/11/90.TH vp 4 VAX "" Unsupported.SH Namevp \- Versatec interface.SH Syntax.B "device vp0 at uba0 csr 0177510 vector vpintr vpintr".SH DescriptionThe Versatec printer/plotter is normally used with the programs.MS vpr 1 ,.MS vprint 1or.MS vtroff 1 .This description is designed for those who wish to drive the Versatec directly..PPTo use the Versatec yourself, you must realize that you cannot open thedevice,.PN /dev/vp0if there is a daemon active.You can see if there is a daemon active by doing a.MS lpq 1 ,and seeing if there are any files being sent..PPTo set the Versatec into plot mode you should include.RI < sys/vcmd.h >and use the.MS ioctl 2call.IPioctl(fileno(vp), VSETSTATE, plotmd);.PPwhere.I plotmdis defined to be.IP\fBint\fR plotmd[] = { VPLOT, 0, 0 };.PPand.PN vpis the result of a call to.PN fopenon stdio.When you finish using the Versatec in plot mode you should eject paperby sending it a EOT after putting it back into print mode, i.e. by.PP'nf	\fBint\fR prtmd[] = { VPRINT, 0, 0 };	\&...	fflush(vp);	ioctl(fileno(vp), VSETSTATE, prtmd);	write(fileno(vp), "\e04", 1);.fi.PP.BR N.B. :If you use the standard I/O library with the Versatec you.B mustdo.IPsetbuf(vp, vpbuf);.PPwhere.PN vpbufis declared.IP\fBchar\fR vpbuf[BUFSIZ];.PPotherwise the standard I/O library, thinking that the Versatecis a terminal (since it is a character special file) willnot adequately bufferthe data you are sending to the Versatec.This will cause it to run.B extremelyslowly and tends to grind the system to a halt..SH RestrictionsThe configuration part of the driver assumes that the device issetup to vector print mode through 0174 and plot mode through0200.  Since the driver doesn't care whether the device considers theinterrupt to be a print or a plot interrupt,it would be preferable to have these be the same.This since the configuration program can't be sure at boot timewhich vector interrupted and where the interrupt vectorsactually are.For the time being,since our versatec is vectored as described above, we specifythat it has two interrupt vectors and are careful to detect aninterrupt through 0200 at boot time and (manually) pretend theinterrupt came through 0174..SH DiagnosticsThe following error numbers are significant at thetime the device is opened..TP 10[ENXIO]The device is already in use..TP[EIO]The device is offline..SH Files.PN /dev/vp0.SH See Alsovfont(5),lpr(1),lpd(8),vtroff(1),va(4)